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Phillip Lougher846b7302013-11-18 02:59:12 +00001#ifndef PAGE_ACTOR_H
2#define PAGE_ACTOR_H
3/*
4 * Copyright (c) 2013
5 * Phillip Lougher <phillip@squashfs.org.uk>
6 *
7 * This work is licensed under the terms of the GNU GPL, version 2. See
8 * the COPYING file in the top-level directory.
9 */
10
Phillip Lougher0d455c12013-11-13 02:04:19 +000011#ifndef CONFIG_SQUASHFS_FILE_DIRECT
Phillip Lougher846b7302013-11-18 02:59:12 +000012struct squashfs_page_actor {
13 void **page;
14 int pages;
15 int length;
16 int next_page;
17};
18
19static inline struct squashfs_page_actor *squashfs_page_actor_init(void **page,
20 int pages, int length)
21{
22 struct squashfs_page_actor *actor = kmalloc(sizeof(*actor), GFP_KERNEL);
23
24 if (actor == NULL)
25 return NULL;
26
27 actor->length = length ? : pages * PAGE_CACHE_SIZE;
28 actor->page = page;
29 actor->pages = pages;
30 actor->next_page = 0;
31 return actor;
32}
33
34static inline void *squashfs_first_page(struct squashfs_page_actor *actor)
35{
36 actor->next_page = 1;
37 return actor->page[0];
38}
39
40static inline void *squashfs_next_page(struct squashfs_page_actor *actor)
41{
42 return actor->next_page == actor->pages ? NULL :
43 actor->page[actor->next_page++];
44}
45
46static inline void squashfs_finish_page(struct squashfs_page_actor *actor)
47{
48 /* empty */
49}
Phillip Lougher0d455c12013-11-13 02:04:19 +000050#else
51struct squashfs_page_actor {
52 union {
53 void **buffer;
54 struct page **page;
55 };
56 void *pageaddr;
57 void *(*squashfs_first_page)(struct squashfs_page_actor *);
58 void *(*squashfs_next_page)(struct squashfs_page_actor *);
59 void (*squashfs_finish_page)(struct squashfs_page_actor *);
60 int pages;
61 int length;
62 int next_page;
63};
64
65extern struct squashfs_page_actor *squashfs_page_actor_init(void **, int, int);
66extern struct squashfs_page_actor *squashfs_page_actor_init_special(struct page
67 **, int, int);
68static inline void *squashfs_first_page(struct squashfs_page_actor *actor)
69{
70 return actor->squashfs_first_page(actor);
71}
72static inline void *squashfs_next_page(struct squashfs_page_actor *actor)
73{
74 return actor->squashfs_next_page(actor);
75}
76static inline void squashfs_finish_page(struct squashfs_page_actor *actor)
77{
78 actor->squashfs_finish_page(actor);
79}
80#endif
Phillip Lougher846b7302013-11-18 02:59:12 +000081#endif